Limits...
Movement of feeder-using songbirds: the influence of urban features

View Article: PubMed Central - PubMed

ABSTRACT

Private gardens provide vital opportunities for people to interact with nature. The most popular form of interaction is through garden bird feeding. Understanding how landscape features and seasons determine patterns of movement of feeder-using songbirds is key to maximising the well-being benefits they provide. To determine these patterns we established three networks of automated data loggers along a gradient of greenspace fragmentation. Over a 12-month period we tracked 452 tagged blue tits Cyantistes caeruleus and great tits Parus major moving between feeder pairs 9,848 times, to address two questions: (i) Do urban features within different forms, and season, influence structural (presence-absence of connections between feeders by birds) and functional (frequency of these connections) connectivity? (ii) Are there general patterns of structural and functional connectivity across forms? Vegetation cover increased connectivity in all three networks, whereas the presence of road gaps negatively affected functional but not structural connectivity. Across networks structural connectivity was lowest in the summer when birds maintain breeding territories, however patterns of functional connectivity appeared to vary with habitat fragmentation. Using empirical data this study shows how key urban features and season influence movement of feeder-using songbirds, and we provide evidence that this is related to greenspace fragmentation.

No MeSH data available.


Related in: MedlinePlus

The frequency of connections (i.e. functional connectivity) of two species of garden bird moving between bird feeders, within (a) the network of low fragmentation, (b) the network of medium fragmentation, (c) the network of high fragmentation. Connections occurred over a 12-month period. The upper panel rasters were generated using hyperspectral and LiDAR data (Appendix S1), we show the location of rfid bird feeders in red. Habitat classification: white; vegetation free surfaces at ground level, light grey, buildings; medium grey, grass & low lying vegetation, dark grey; vegetation (at 2 m resolution). The lower panels show the frequency of each connections (black line, >100; dark grey line, >50–100; medium grey line, >10–50; light grey line, 1–10) and the total number of connections made by each feeder (divided into 4 categories denoted by increasing size and brightness of the red circle: 0; 10; 50; 100; >200). ♦ Bird catching locations. Images were created in R version 3.1.234. *To increase the clarity of the image only those connections that occurred between feeder pairs that were less than the mean distance between all feeder pairs are shown (<213 m); this only loses 9% of the total connections made, and does not exclude any feeder pairs with =>10 connection.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC5120271&req=5

f1: The frequency of connections (i.e. functional connectivity) of two species of garden bird moving between bird feeders, within (a) the network of low fragmentation, (b) the network of medium fragmentation, (c) the network of high fragmentation. Connections occurred over a 12-month period. The upper panel rasters were generated using hyperspectral and LiDAR data (Appendix S1), we show the location of rfid bird feeders in red. Habitat classification: white; vegetation free surfaces at ground level, light grey, buildings; medium grey, grass & low lying vegetation, dark grey; vegetation (at 2 m resolution). The lower panels show the frequency of each connections (black line, >100; dark grey line, >50–100; medium grey line, >10–50; light grey line, 1–10) and the total number of connections made by each feeder (divided into 4 categories denoted by increasing size and brightness of the red circle: 0; 10; 50; 100; >200). ♦ Bird catching locations. Images were created in R version 3.1.234. *To increase the clarity of the image only those connections that occurred between feeder pairs that were less than the mean distance between all feeder pairs are shown (<213 m); this only loses 9% of the total connections made, and does not exclude any feeder pairs with =>10 connection.

Mentions: In total we tagged 452 individuals of two common species of feeder-using birds (blue tit Cyanistes caeruleus and great tit Parus major) between June 2013 and August 2014 (see Supplementary Table S1 and Fig. S1). We divided the year into four equal seasons: summer, autumn, winter, spring. We then considered that a tagged bird visiting first one and then a different feeder within each network and within each season made a connection, with data collection starting on the 1st September 2013. Across the three networks, 51% (±2 SD) of tagged individuals made one or more connections between feeders (n = 9,848; Fig. 1). Eighty-eight percent of connections occurred within two days (n = 8,652; See Supplementary Fig. S2). We discarded from the analysis connections that took longer to make because we considered there was a high probability that birds travelled to the second feeder via a non-direct route. Using hyperspectral and LiDAR data we categorised the habitat in an ellipsoid between feeder pairs to establish variation in urban form across the three networks of RFID readers (Table 1). For each feeder pair we calculated the distance between feeders, the shortest distance between feeders and a bird catching site, and finally within each ellipsoid we calculated vegetation cover and the number of road gaps (Table 1; Fig. 1).


Movement of feeder-using songbirds: the influence of urban features
The frequency of connections (i.e. functional connectivity) of two species of garden bird moving between bird feeders, within (a) the network of low fragmentation, (b) the network of medium fragmentation, (c) the network of high fragmentation. Connections occurred over a 12-month period. The upper panel rasters were generated using hyperspectral and LiDAR data (Appendix S1), we show the location of rfid bird feeders in red. Habitat classification: white; vegetation free surfaces at ground level, light grey, buildings; medium grey, grass & low lying vegetation, dark grey; vegetation (at 2 m resolution). The lower panels show the frequency of each connections (black line, >100; dark grey line, >50–100; medium grey line, >10–50; light grey line, 1–10) and the total number of connections made by each feeder (divided into 4 categories denoted by increasing size and brightness of the red circle: 0; 10; 50; 100; >200). ♦ Bird catching locations. Images were created in R version 3.1.234. *To increase the clarity of the image only those connections that occurred between feeder pairs that were less than the mean distance between all feeder pairs are shown (<213 m); this only loses 9% of the total connections made, and does not exclude any feeder pairs with =>10 connection.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC5120271&req=5

f1: The frequency of connections (i.e. functional connectivity) of two species of garden bird moving between bird feeders, within (a) the network of low fragmentation, (b) the network of medium fragmentation, (c) the network of high fragmentation. Connections occurred over a 12-month period. The upper panel rasters were generated using hyperspectral and LiDAR data (Appendix S1), we show the location of rfid bird feeders in red. Habitat classification: white; vegetation free surfaces at ground level, light grey, buildings; medium grey, grass & low lying vegetation, dark grey; vegetation (at 2 m resolution). The lower panels show the frequency of each connections (black line, >100; dark grey line, >50–100; medium grey line, >10–50; light grey line, 1–10) and the total number of connections made by each feeder (divided into 4 categories denoted by increasing size and brightness of the red circle: 0; 10; 50; 100; >200). ♦ Bird catching locations. Images were created in R version 3.1.234. *To increase the clarity of the image only those connections that occurred between feeder pairs that were less than the mean distance between all feeder pairs are shown (<213 m); this only loses 9% of the total connections made, and does not exclude any feeder pairs with =>10 connection.
Mentions: In total we tagged 452 individuals of two common species of feeder-using birds (blue tit Cyanistes caeruleus and great tit Parus major) between June 2013 and August 2014 (see Supplementary Table S1 and Fig. S1). We divided the year into four equal seasons: summer, autumn, winter, spring. We then considered that a tagged bird visiting first one and then a different feeder within each network and within each season made a connection, with data collection starting on the 1st September 2013. Across the three networks, 51% (±2 SD) of tagged individuals made one or more connections between feeders (n = 9,848; Fig. 1). Eighty-eight percent of connections occurred within two days (n = 8,652; See Supplementary Fig. S2). We discarded from the analysis connections that took longer to make because we considered there was a high probability that birds travelled to the second feeder via a non-direct route. Using hyperspectral and LiDAR data we categorised the habitat in an ellipsoid between feeder pairs to establish variation in urban form across the three networks of RFID readers (Table 1). For each feeder pair we calculated the distance between feeders, the shortest distance between feeders and a bird catching site, and finally within each ellipsoid we calculated vegetation cover and the number of road gaps (Table 1; Fig. 1).

View Article: PubMed Central - PubMed

ABSTRACT

Private gardens provide vital opportunities for people to interact with nature. The most popular form of interaction is through garden bird feeding. Understanding how landscape features and seasons determine patterns of movement of feeder-using songbirds is key to maximising the well-being benefits they provide. To determine these patterns we established three networks of automated data loggers along a gradient of greenspace fragmentation. Over a 12-month period we tracked 452 tagged blue tits Cyantistes caeruleus and great tits Parus major moving between feeder pairs 9,848 times, to address two questions: (i) Do urban features within different forms, and season, influence structural (presence-absence of connections between feeders by birds) and functional (frequency of these connections) connectivity? (ii) Are there general patterns of structural and functional connectivity across forms? Vegetation cover increased connectivity in all three networks, whereas the presence of road gaps negatively affected functional but not structural connectivity. Across networks structural connectivity was lowest in the summer when birds maintain breeding territories, however patterns of functional connectivity appeared to vary with habitat fragmentation. Using empirical data this study shows how key urban features and season influence movement of feeder-using songbirds, and we provide evidence that this is related to greenspace fragmentation.

No MeSH data available.


Related in: MedlinePlus